The present invention relates to a lever engagement type electric power source circuit breaker. Especially, the present invention relates to a lever engagement type electric power source circuit breaker suitably used for temporarily cutting off an electric current in a circuit at the time of inspection and maintenance of an electric vehicle or a hybrid vehicle having a high voltage circuit for driving a motor.
In an electric vehicle or a hybrid vehicle, a battery capacity is larger than that of a usual gasoline engine vehicle. Therefore, when a maintenance work is executed for an electric system of the vehicle, an electric power source circuit is opened by an electric circuit breaker so as to ensure the safety of the maintenance work. Therefore, a lever engagement type electric power source circuit breaker is conventionally known, by which an electric power source is cut off when a service plug attached to a terminal portion, which is connected to the electric power source circuit, is disconnected. Concerning this breaker, for example, refer to Patent Document JP-A-2003-100382.
In FIGS. 14 to 16, a lever engagement type electric power source circuit breaker 101A for an electric circuit of a high voltage and a high intensity of electric current is shown. The lever engagement type electric power source circuit beaker 101A includes a first connector housing 101 made of synthetic resin, a lever 102 made of synthetic resin attached to this one connector housing 101, a second connector housing 103 made of synthetic resin to which one connector housing 101 is attached when this lever 102 is operated.
As shown in FIG. 16, the first connector housing 101 includes a housing body 104 made of synthetic resin, and a cover 105 made of synthetic resin attached to the housing body 104 so that the cover 105 can close an upper portion of the housing body 104. On the housing body 104, a pair of protrusions 106 is provided. These protrusions have triangular pyramid shape. As the pair of protrusions are inserted into engagement holes 107 on the cover 105, the cover 105 is attached to the housing body 104. The conventional lever engagement type electric power source circuit breaker 101A has the cover 105 described above for a purpose of insulation so that fingers of an operator can not be easily contacted with terminals and fuses (not shown) incorporated into the connector housing 101.
A pair of first bosses 111 for guiding is protruded from an outer wall of the housing body 104. As shown in FIGS. 14 and 15, the pair of bosses 111 for guiding are respectively engaged with the guide grooves 120 of the lever 102. In a pair of arm plate 118a, 118b of the lever 102, the cam grooves 121 are symmetrically formed. When the first connector housing 101 is attached to the second connector housing 103, the bosses 136 used for a cam of the other connector housing 103 are inserted into the pair of cam grooves 121.
When the lever 102 is rotated about the first bosses 111 as shown in FIG. 15(a) under the condition that the second bosses 136 are inserted into the cam grooves 121, the connector housings 101 and 103 are engaged with each other at the rotation finishing position (shown in FIG. 15B) of the lever 102. In this way, terminals (not shown) of both the connectors are electrically engaged with each other. After the rotation of the lever 102 is finished, the lever 102 is moved straight under the guide of grooves 120 with respect to the first bosses 111 and the guide of the cam grooves 121 with respect to the second bosses 136. Then at the straight movement finishing position (shown in FIG. 15C), an engagement detection switch (not shown) is turned on and an electric power source circuit (not shown) is electrically connected.
In order to cut off the electric power source circuit, a reverse operation to the operation described above is executed. That is, when the lever 102 is moved straight from the state (shown in FIG. 15C)) in which the engagement detection switch is turned on, to the engagement detection switch is released. At the rotation finishing position (shown in FIG. 15B) of the lever 102, the engagement detection switch is turned off and the electric power source circuit is cut off.